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The physical work environment in the Aerosol Production Department of PT XYZ experienced problems related to excessive room temperatures reaching 37.3°C and chemical odor pollution caused by vapor recirculation from the coating oven process. These conditions potentially reduced operator comfort and concentration. This study aimed to analyze the effectiveness of the Kaizen approach through the Plan-Do-Check-Act (PDCA) cycle in controlling production room temperature and improving air quality. A quantitative descriptive method with an Action Research approach was employed. Problem identification and root cause analysis were conducted using the 7 QC Tools, particularly the Pareto Diagram and Fishbone Diagram. Improvement actions included the installation of turbine ventilators, aluminum foil roof insulation, and a 3-meter vertical exhaust ducting system. The results showed that the average room temperature decreased from 34.6°C to 27.4°C, representing a reduction of 7.2°C, while the peak daytime temperature decreased by 8.7°C and met the established threshold limit value. In addition, chemical odor pollution was completely eliminated. Therefore, the Kaizen-PDCA approach proved effective in improving the physical work environment sustainably.

The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.

The low thermal efficiency of Gas Power Plants (PLTG) due to exhaust gas heat loss drives the implementation of cogeneration at PLTGU Block II PT. PLN Indonesia Power UBP Semarang. This study analyzes the performance of the Gas Turbine Generator (GTG), combined cycle efficiency, and Exergy distribution using a 3-3-1 configuration. The research utilizes actual operational data from January 28, 2026, sampled at 10-minute intervals. Results indicate that cogeneration via a Heat Recovery Steam Generator (HRSG) significantly enhances plant efficiency. The GTG output ranged from 273–283 MW with an efficiency of 30.0–30.2%. Following combined cycle integration, system efficiency increased to 43.9–44.4%, a gain of approximately 14%, with a heat rate of 11,916–11,988 kJ/kWh. Exhaust heat of 665–713 MW was recovered to generate an additional 130 MW through the Steam Turbine Generator (STG). Exergy analysis reveals that the largest irreversibility occurs in the GTG combustion process (285 MW), followed by the HRSG (185 MW) and STG (49 MW).

The foundation of turbine machines in industrial buildings must be able to withstand static and dynamic loads caused by operational vibrations. Generally, reinforced concrete block foundations are used due to their good stability. However, under certain conditions such as limited land, decreased soil bearing capacity, and the need for structural rehabilitation, their application becomes less effective. Therefore, this study aims to analyze the use of Micropile foundations as an alternative for turbine machine foundations at Candi Baru Sugar Factory, Sidoarjo.The research method includes literature studies, soil data collection through Cone Penetration Test (CPT), machine technical data analysis, and the design and analysis of Micropile foundations. The analysis covers bearing capacity, settlement, dynamic response, pile cap design, and cost estimation.The results indicate that Micropiles with a diameter of 0.20 m, a length of 2 m, five piles, and a pile cap size of 2 m × 2 m × 4.5 m are able to safely and stably support the machine load. In addition, this system is considered more efficient in terms of construction time and implementation. Therefore, Micropile foundations are recommended as an effective and economical alternative for turbine machine foundations.

Gas turbine generators play an important role in providing electrical energy, especially in the maritime sector, but they are vulnerable to disturbances such as overcurrent and undervoltage, which can cause equipment damage. This study aims to design and test an automatic protection system based on the ESP32 microcontroller with the INA219 sensor to detect current and voltage, as well as a relay as a circuit breaker. The method used is an experimental approach including static and dynamic testing, both with and without a 5W AC lamp load as a simulation of real loading conditions. Test results show that the average sensor reading error is 2.65% for current and 1.76% for voltage, which is still within the ±3% tolerance limit. The system is able to disconnect the load when any parameter exceeds the protection threshold, although there are slight inconsistencies in the relay response due to sensor reading fluctuations. In conclusion, this automatic protection system is proven to be 85% accurate and responsive in maintaining the operational reliability of the gas turbine generator, making it applicable as a preventive solution against electrical disturbances in marine environments.

The energy that is stored in water can be used to generate electricity by taking advantage of the potential energy available, like the energy from waterfalls and the movement of flowing water. Micro-hydropower plants (PLTMH) are one solution to address the energy crisis, particularly in electricity. VDI 2221 is a method that German engineers use as a guideline when designing construction projects. The VDI (Verein Deutsher Ingeneure or German Engineers Association) design process involves several stages: task description, design concept determination, physical design, and detailed design. Based on the solution principle matrix table, 3 variants were obtained, each of which has criteria. Of the 3 variants that have been evaluated, variant 2 was obtained with results that met the requirements. The cost analysis table shows that the total cost for designing a prototype test equipment for a micro-hydroelectric power plant (PLTMH) based on a laboratory-scale crossflow turbine is Rp 10,032,000. This cost includes instrumentation, control and electrical panels, measuring instruments, pipe instruments, frame and casing, and unforeseen costs.